Inkjet printhead assemblies include an ejection chamber, an ejection member, a chamber opening, and a fluid ejection channel. The ink levels of inkjet printhead assemblies are monitored using various methods. One method of monitoring the level of fluid is by counting the drops of fluid ejected from the printhead. Other methods include positioning an additional sensor either on the printhead near ink access points or external to the printhead, but near the printhead to detect ink from a nozzle.